Newsletter

How many tornados hit city remains big mystery

Published May 6, 1990

In the frightening hours after the tornado hit, survivors and researchers pondered a still-unsolved mystery: How many tornados ravaged downtown Lubbock?

Damage was extensive. One report said as many as three tornados converged and joined as one for the blitz of destruction between downtown and Lubbock Municipal Airport. Another suggested a meandering tornado that looped in the downtown area.

And now?

"I'm convinced there was one big tornado," James R. McDonald, director of Tech's Center for Disaster Research, said early this year. "There may have been a second tornado, but a monster tornado creates strong inflow into the main funnel. I don't believe it was a looping tornado like so many people believe.

"In a big, monstrous, circulating system, a lot of different things can happen," McDonald said. "It was dark, I don't know if we'll ever know the answer to that."

The night of terror included hail the size of grapefruit and a tornado that traveled along or near the ground south of the city for two miles and 1 1/2 hours before the downtown was hit.

Since the tornado, Tech researchers - the same ones that scrutinized the damaged downtown area for 1 1/2 years before publishing the most detailed account of an urban tornado - concluded that one massive tornado likely formed above the downtown area and traveled north-northeast.

"Based on our looking at ground damage ... it seems reasonable that winds came in from a large area," said Kishor Mehta, director of Tech's Wind Engineering Research Center.

"This was very large and wide. It appeared that winds came from as far west as Tech, from Fourth Street and the Brownfield Highway, and as far east as the loop. All of the winds merged toward the center of the tornado.

"One tornado seems most logical from the ground surveys," he said. "There was scattered damage at the edges. Most of the severe destruction was from the downtown area to the airport."

Research conducted immediately after the tornado estimated that maximum wind speeds at the storm's center reached 163 to 290 mph.

But Mehta said current estimates put the wind speed at 180 to 200 mph on the ground in the downtown area and 250 mph at the top of the Great Plains Life Building, now the Metro Tower Building.

Wind speeds generally are lower at ground level because of friction, he said.

T.T. Fujita, a researcher at the University of Chicago who directed a team that arrived in Lubbock within hours of the storm, argued that two tornados formed behind an advancing moist front that had a very small temperature difference across it - unlike the normal trigger of warm moist air meeting cold air.

Fujita's team studied "suction spots." It found that, at one point east of downtown, the wind speed and suction were strong enough to topple 13 cement beams - each weighing 54,500 pounds - from a U.S. 82 overpass.

The large tornado, Fujita theorized, made a loop just north of Tech and headed northeast with a rotation speed of 145 to 290 mph.

A meteorological theory by N.F. Somes, R.D. Dickkers and T.H. Boone suggested that two tornados touched down simultaneously east of Tech, one near Jones Stadium and the other to the southeast. The tornados, which did not maintain constant ground contact, merged north of downtown and stayed on the ground as the storm moved over the airport.

Another meteorological theory by Tech researchers, including Mehta, at first suggested that three tornados struck between 9:35 p.m. and 10:06 p.m.

The first formed over downtown and moved south-southwest to the north-northeast of downtown, damaging tall buildings.

The second formed northeast of Jones Stadium and moved east, leaving a one-mile stretch of destruction before it joined the first tornado north of downtown, expanded, and left a l'/2-mile-wide path of destruction.

The third tornado formed just north of the merger point. The researchers noted damage patterns and recorded time of arrival of severe winds at various locations.

The Institute for Disaster Research, which was born as a result of the Lubbock tornado, found arguments for all three theories, but its researchers decided that the disorganized pattern of structural damage was the result of the differing abilities of different structures in a 15-square-mile area to resist wind forces.